Another theory that seems to be gaining in popularity is the “multi-component hypothesis.” It is suggested that between the normal protein (PrPC) and the formation of the prion (PrPRes/PrPSc) there are intermediate steps in which prions are composed of multiple host components rather than just PrPC alone. The current hot question in prion research is whether or not something else (besides PrPRes/PrPSc) is needed for prion disease to occur or be transmitted.